Cannibalism and tail biting are two well-known manifestations of aggressiveness in pigs and sows.
The most frequent manifestation of cannibalism is the sow which eats its young. There are various causes for this phenomenon, including late transfer to the farrowing shed, farrowing pains, the presence of a noisy or unknown person, mastitis, etc. Cannibalism may also occur following changes in breeding conditions, mixing of litters, transportation, or in one and the same litter when a pig is attacked by its congeners.
Tail biting is common among young animals. All the pigs of one and the same sty progressively have their tails bitten by one or two congeners. The lesions caused always have serious consequences: the pig that has been bitten suffers, becomes timid and no longer takes food. The stub of the tail becomes infected and the resulting degeneration of the spinal cord can cause paralysis.
There are various reasons for tail biting. It can be caused by feed problems, including severe rationing, unappetising or unbalanced food, sudden changes in ration, disturbed timetables, lack of water, insufficient feeding troughs. Tail biting can also be caused by the particular ambient conditions prevailing: excessively bright light, noise, inspections, storms, inadequate ventilation, high temperature, humidity, lack of space, the introduction of an animal into an already existing litter, damp, cold bedding, etc. Solutions to these problems that have already been proposed are either relatively ineffectual or too painful to the animal and, hence, prejudicial to its development.
Thus, it has been proposed either to cut the teeth of the young piglets or to cut their tails with forceps or with a rubber ring. It has also been proposed to apply theoretically repulsive products based on gas oil or on Norwegian pine oil, but unfortunately these products have no practical effectiveness.
It has now been found that the manifestations of aggression described above can be avoided by spraying a composition containing one or more hydroxy quinoline derivatives as its principal active material onto those parts of the animal capable of being attacked by its congeners.
The following compounds are examples of the 8-hydroxy quinoline derivatives which can be used for this purpose:
- 8-hydroxy quinoline and its organic salt such as its citrate, tartrate, sorbate, cinnamate; PA1 - the double sulphate of 8-hydroxy quinoline and potassium; PA1 The sulphate of hydroxy quinoline and potassium; PA1 - 5-chloro-8-hydroxy quinoline; PA1 - 5,7-dibromo-8-hydroxy quinoline; PA1 - 5,7-diiodo-8-hydroxy quinoline; PA1 - 5-chloro-7-iodo-8-hydroxy quinoline; PA1 - 5-nitro-8-hydroxy quinoline; PA1 - 7-iodo-8-hydroxy quinoline-5-sulphonic acid and its alkali metal salts; PA1 - the methyl sulphate of N-methyl-8-hydroxy quinolinium; PA1 - 8-hydroxy quinoline iodo bismuthate; PA1 - the 8-hydroxy quinoleate of bismuth or aluminium copper and zinc; PA1 - 8-hydroxy quinoline benzoate; PA1 - 8-hydroxy quinoline sulphathiazole phthalate; PA1 - 8-hydroxy quinoline salicylate; PA1 - 8-hydroxy quinoline-5-sulphonic acid and its heavy metal salts (aluminium, bismuth, copper, zinc); PA1 - 8 hydroxy quinoline hydrochloride; PA1 - phosphorus derivatives of 8-hydroxy quinoline.
The mechanism responsible for the repulsive effect of the compositions according to the invention is not known in any detail, although the results obtained have been extremely spectacular and unexpected, a property of this nature never having been described in the past.
To enable them to be conveniently used by the consumer, the above hydroxy quinoline derivatives will generally be formulated with suitable fillers and/or additives and, if necessary, with other active materials capable of complementing the activity of the products according to the invention.
The formulations used in the method of this invention will preferably be liquid formulations or solid formulations which can be diluted with water or in a suitable solvent before application.
The formulations can be in the form of aqueous solutions in cases where the hydroxy quinoline derivative used is sufficiently soluble in water.
They can also be made up in the form of wettable powders containing the active material in dispersion in an inert filler optionally admixed with a surfactant or with antilumping agents or deflocculants.
The following are examples of compositions according to the invention: Composition A ______________________________________ neutral 8-hydroxy quinoline sulphate 200 double sulphate of hydroxy quinoline and potassium 100 water q.s.f. 1000 ______________________________________
This composition is in the form of an aqueous solution which is ready for use.
______________________________________ Composition B ______________________________________ 5-nitro-8-hydroxy quinoline 100 8-hydroxy quinoline sulphathiazole phthalate 50 8-hydroxy quinoline salicylate 50 inert filler 800 ______________________________________